Logwood dyeing



WHITE EXTRACTING COMPANY, OF NEW JERSEY.

- WILLIAM A. FELD-ER, or wns'r oonnmeswoon, vEwJnRsnY, ssIeNonroTAYLon CAMDEN, NEW JERSEY, a CORPORATION'OF LOGWOOD DYEING.

No Drawing.

To all whomit may concern:

Be it known that I, XVILLI A. FELDnn, a

citizen of the United States, residing at est Collingswood, in the- 'county of Camden and State of New Jersey, have invented a new and useful Improvement in Logwood Dyeing, of which the following is a specification. p 7

.Animal fibers and textiles and fabrics of the same can be and are dyed black with logwoocl in such a way that they will .be fast, but to do this two baths are required, one containing the mordant in which the goods, stock or fabric of animal fibers are treated, for example, for anhour anda half, and the other containing logwood or logwood dye, as hematine, in which the mordanted goods after having been rinsed, are treated for example, for another hour and a half. Efforts have been made to dye animal fibers black with logwood with a single bath containing logwood dye, as hematine or the like, along with the mordant, but such ,efforts have not been commercially successful, because the product is blue rather than black and in order to make it black the quantity of chemicals and logwood employed is excessive, which makes the goods harsh and crack very badly.

The principal object of the present invention is to improve, facilitate and cheapen the art of dyeing animal fibers and fabrics.

and textiles containing the same black with logwood dyes and this I do by using one bath and saving dye chemicals, steam, wa-

ter, labor and time, and I obtain dyed prod-.

ucts which although black are fast.

To this and other ends hereinafter set forth, the invention comprises the improved step in the art of dyeing animal fibers and fabrics and textiles containing the same black with logwood dye and known mordants which consists in subjecting the same to the action of nitrites, or chlorates as of sodium which are salts that part with their oxygen with facility and which have the ef-' fect of intensifying or developing the color which would. be produced without them and V of making it black and of such quality and character that it will be fast.

To. practice the invention with one bath the following procedure may be adopted in substance: The bath of course contains water and substantially the following ingredients in the following proportions by weight:

' Specification of -Letters Patent.

oxalic acid; 2% copper sulphate; 3% iron Patented Apiu i, 192 2. I Application filed May 19, 1921. Serial No. 470,952.

sulphate; and 1% chlorate of sodium.' In 3 i this bath the animal fibers or fabric or textile containing the same is treated for about an hour and a half at boiling point.- To those skilled in the art it willv be apparent that the novel ingredient in the bath is chlo-' rate of sodium and that the quantity of dye and mordant is comparatively small. The invention may also be practiced by the use of a bath containing substantially the f0l lowing ingredients in the proportions by weight nowto be'given: 6% hematine or logwood crystals; 3% oxalic acid; 2% copper sulphate; and 3% iron sulphate. In this bath the material of animalorigin may be boiled for an hour and a half and then there is added carbonate of sodium, after which the bath is let cool and 2% of nitrite of sodium is added. 1

I Fromthe foregoing it will be evident that the use of nitrite, or chlorate of sodium in conneotionwiththe logwood dyeand mordant constitutes the. gist of the invention,

and while these salts are bodies adapted to.

part with their oxygen with facility and to intensify the color which would beproduced without them and to make it black and of such quality that it will be fast, I do not limit my invention to those particular bodies or quantities thereof, because I desire to reserve the benefit of the broader doctrine of equivalents applicablein'chemical cases,

and it is quite likely that chemists will know of equivalents of those salts. Whileit is. of course an advantageous feature of my in- 'vention that with one bath a good fast black can beproduced in a short time from logwood dyes, still I realize that it is possible to practice my invention by first dyeing the textiles or fabrics containing animal fibers in a bath with the logwood dyesand mor dant and then transferring them, for ex- I ample, to a cold bath of nitrite-of sodium and acid. I therefore claim such. procedure as'being a use of my invention.

There is nothing particularly new about the mordants above referred to but if used However the Y with logwood dye with a single bath, the resulting color would be blue. chlorates, or nitrites make the. color black but if too large a quantity of them is used the colorwill be brown, and this furnishes a good working way in which to determine the quantity of those salts that should be employed and leads to my belief that their-action is to part with their oxygen and oxidize the logwood dye and in that way make it possible to obtain in a single bath a full fast black similar to that obtained by the twobath method. It may be said that animal fibers or fabrics or textiles containing the same which have been dyed a more or less bluish COlOr by known methods with logwood can be made black by means of the de scribed nitrites. In some cases other dyes as fustic may be used in addition to logwood dyes.

I claim:

"1. In the artof dyeing animal fibers and fabrics or textiles of the same black with logwood and mordants, the improved step, which consists in subjecting the same to the action of sodium salts. of the oxygen acids of the non-metallic groups 5 and 7 and which part with oxygen with facility and intensify the color and make it a fast black.

2. In the art of dyeing animal fibers and fabrics or textiles of the same black with logwood and mordant-s the improved step which consists in subjecting the sagne tothe action of a salt of nitrous acid.

- 3. In the art of dyeing animal fibers and fabrics or textiles of the same black with logwood and mordants the improved step which consists in subjecting the same tothe action of nitrite of sodium.

4. The art of dyeing animal fibers and fabrics or textiles of the same black which consists in subjecting them to a single bath containing lo'g'wood dye and mordants and an oxidizing agent.

5. The art of dyeing animal fibers and fabrics or textiles of the same black which consist in subjecting them to a single bath containing logwood dye and mordants and thereafter adding carbonate of sodium and nitrite of sodium to the bath.

WILLIAM A. FELDER. 

